If songwriter Billy Joel were to rework one of his most famous songs, how might he describe the “New York state of mind” of the city’s NFL fans? Maybe “anxious” or “angry” or both after a week in which the defending Super Bowl champion Giants were humbled, 34-0, by the Atlanta Falcons and the Jets saw their last, faint playoff hopes snuffed out by the Tennessee Titans, 14-10. In the latter game, Jets quarterback Mark Sanchez committed five turnovers, including one on each of the team’s last three possessions. To test your knowledge of Week 15 developments, take this 16-question quiz.